Addition agents and mineral oil lubricant compositions containing the same



' Patented July 15, 1952 LUBRICANT COMPOSITIONS CON- TAINING THE SAME Herschel G. Smith, Wallingford, and Troy L. Cantrell, Lansdowne, Pa., assignors to Gulf Oil Corporation, Pittsburgh, Pa., a corporation of Pennsylvania No Drawing. Application July 6, 1948, Serial No. 37,308

Claims.

This invention relates to addition agents and mineral oil lubricant compositions containing the same and, more particularly, it is concerned with improvement agents which confer improved antioxidant, corrosion-inhibiting and detergency properties on mineral oil lubricants.

It is recognized in the art that mineral oil lubricants are readily oxidized under service conditions thereby reducing the service life of internal combustion engines and steam turbines. A concomitant effect is corrosion of bearing surfaces. These problems become particularly acute when a highly refined paraliinic base mineral oil is employed as the lubricant. I

In the lubrication of internal combustion engines of all -ty pes, particular1y when severe operating conditions are encountered, mineral lubricating oils frequently prove unsatisfactory be- ,.cause they tend to deposit varnish, gum and sludge on the engine surfaces, such as the cylinder walls, pistons and rings, and also to induce corrosion of bearing materials thereby causing failure of the engine. These problems have become increasingly serious because of the trend toward higher efiiciency or higher power output per unit weight of engine, Whichresults in conditions tending, to accelerate the deteriorating influences on the mineral oil lubricant. The formation of so-called varnishes and sludges on engine surfaces is a result of oxidation effects on the lubricating oils. The presence of gums, varnishes and sludges is detrimental for many reasons. These substances tend to increase ring sticking and accelerate the formation of further deposits on piston surfaces and in fixed parts of the combustion chamber. The sludges formed in the crankcase of the engine increase the rate of corrosion of bearing surfaces, especially of bearing alloys of the types now in use.

In steam turbines. the corrosion problem is particularly acute because of the presence of water in the mineral oil lubricant and in addition to bearing corrosion, rusting may also be encountered.

It is an object of this invention, therefore to prepare an improvement agent which will obviate the oxidation and corrosion difficulties encountered in the use of mineral oil lubricants.

It is a further object of this invention to provide improved mineral oil lubricant compositions which are stable in storage and use and in which oxidation and corrosion effects are materially inhibited.

In our copending application Serial No. 718,902,

filed 'l?ecember"27, 1946, there is disclosed and claimed an addition agent for mineral oil lubricants which confers excellent antioxidant, corrosion-inhibiting and pressure-carrying properties on mineral oillubricants; Such improvement agent is prepared by heatingan' essentially paraffinic base lubricating oil with aluminum chloride, removing aluminum chloride from the reaction product and reacting said product with phosphorus pentasulfideat an elevated temperature to incorporate phosphorus and sulfur therein. I r

In our copending application Serial No. 736,618, filed March 24,; 1947, now 'U. S. Patent No. 2,456,336, there is disclosed and claimed an improvement agent 'formineral oil lubricants which is prepared by heating an essentially paraffinic base lubricating oil with phosphorus pentasulfide in the presence of a surface active silicacontaining solid catalyst. It is shown in that application that when phosphorus pentasulfide is reacted with 'an essentially parafiinic base lubricatingoil in the presence of a surface active silica-containing solid catalyst, the prior aluminum chloride treatment of the lubricating oil as disclosed in our application Serial No. 718,902 may, be omitted. It is also shown in our latter filed application that when the prior aluminum chloride treatment of the parafiinic base lubricatingoil is combined with reaction of the aluminum chloride treated product with phosphorus pentasulfide in the presence of a surface active silica-containing catalyst, lighter colored products are obtained. e

The objects of the present invention are accomplishedby providing improvement agents for mineral oil lubricants by reacting an essentially paraflinic base lubricating oil or the aluminum chloride treated product thereof with phosphorus pentasulfide, through the use of any of the methods disclosed in our copending applications Serial Nos. 718,902 and 736,618, new U. S. Patent No. 2,456,336, and with an alkylated phenyl phosphite prepared in accordance with U.- S. Patent 2,253,227 to Cantrell andTurner. Such improvement agents, as well asthe mineral oil lubricant compositions containing them, are believed t obe novel and are considered partsof our invention. The present invention may be regarded as an improvement overthe inventions disclosed in our above-identified copending applications. While the addition agents disclosed therein confer excellent antioxidant, pressure-carrying properties Onmineral oil-lubricants, they,sometimes'fail to pass the wellknown, Copper. Strip Test (Method- 530 .31, Federal Spool-'- corrosion-inhibiting andthe so-called corrosive sulfur.

3 fication VV-L-79lc, May 12, 1945, page 259) thus indicating the presence of elementary sulfur or While we do not wish to be bound by any theory. as to the exact natureof the phosphorus pentasulfidereaction products with an essentially parafiinic base lubricating oil, it is our present belief that either elementary sulfur or incompletely bound.

sulfur or both are formed in the reaction. In accordance with the present invention, such elementary or incompletely bound sulfur is neutralized or accepted by combination with the alkylated phenyl phosphite added. in the preparation of the phosphorus pentasulfide reaction parafiinic base lubricating oil is employed are r not fully understood. However, the use of at least one of these methods is essential for the practice of our invention since, if the prior aluminum chloride treatment'or the use of a surface active silica-containing catalyst is omitted, the advantageous results of our invention are not obtained. In order to obtain the results of our invention, therefore, it is necessary (1) to employ an essentially parafiinie base lubricating oil, and

with conventional methods and may be refined in accordance with methods known in the art. If it is desired to treat the essentially paraflinic base lubricating oil with aluminum chloride, such treatment is accomplished as described in our copending application, Serial No. 718,902.

Briefly, such treatment comprises heating the essentially paraifinic' base lubricating oil with from 1 to 20 per cent by weight of anhydrous aluminum chloride at a temperature of from 150 to 300 F. while the mixture is vigorously agitated. The time of treatment may vary in accordance with the amount of aluminum chloride used and the temperature of treatment,

} longer times being required withless aluminum chloride and lower temperatures. In general, the treatment will be completed after four or five hours. After the treatment is completed, agitation is stopped and the sludge containing most of the aluminum chloride settles out from the main body of the oil and is drawn off. The supernatant body of the treated oil may contain further quantities of aluminum chloride finely dispersed therethrough, an'djin order to insure the removal of all aluminum chloride 'fromthe (2) to conduct the reaction of the oil and alkyltreated oil, agitation with an adsorbent clay followed by filtration may be employed. At the higher temperatures of treatment with aluminum chloride some conversion "of the parafiinic base 'oil to lower boiling products may take place.

hereinabove may then be reacted with the alkylated phenyl phosphite and. phosphorus penta sulfide. This. may be accomplished either by reacting with phosphorus pentasulfide per se, as disclosed in our pending application Serial No. 718,902, or in the presence of a surface active silica-containing solid catalyst as disclosed in our copending application, Serial No. 736,618, now U. S. Patent No. 2,456,336.

If it is desired to react the aluminum chloride treated oil and the alkylatedphenyl phosphite with phosphorus pentasul-fide' per se, this reacticn is accomplished by adding from 2 to 20 per cent by weight of P285 on the mixture of oil and phosphite, preferably 5 to 10 per cent, and heat ing with agitation at a minimum reaction temperature of 450 F. and a maximum reaction temperature below the temperature where cracking of the oil begins. Hydrogen sulfide is evolved and when the evolution of hydrogen sulfide has nearly ceased, the temperature of the reaction mixture may be increased within the maximum temperature disclosed above, say to about 500 F. for the completion of the reaction.

If desired, the aluminumchloride treated paraffinic base lubricating oil and the alkylated phenyl phosphite may be reacted with phosphorus pentasulfide in the presence of a surface active silica-containing catalyst; or, the prior aluminum chloride treatment may be omitted and the essentially paraffinic base lubricating oil and alkylated phenylphosphite-may be reacted with phosphorus pentasulfide in thepresence of asurface active silica-containing solid catalyst.

The reaction of the essentially parafllnic base lubricating oil and alkylated phenyl phosphite, whether or not pretreated with aluminum chloride, with phosphorus pentasulfide in the presence of a surface active silica-containing solid catalyst is accomplished byadding 2 to 20; per cent by weight of P235, preferably from 5 to 10 per cent, to the mixture of essentially paramnic base lubricating oil and alkylated phenyl phosphite and heating with agitation at a temperature in the range from 300 F. .to a maximum temperature below the temperature where cracking of the oil, that is, pyrolytic decomposition of the oil, begins. Generally-the minimum cracking temperature of the oil; varies between 490 to 530 depending upon the particular oil' used. The surface-active silicaecontaining. solid catalyst', is employed in amounts of from 210.25 per cent by weight of the reactionm'ixture.charged and preferably in an amount of V 10 per cent by weight. Larger amounts than, 10 percent are ordinarily not necessary, but larger amounts will produce a product having alighter. color), During the course of the reaction hydrogen j'sulfide is evolved and the phosphorus and sulfur become: incorporated in the reaction. product. Whenlthe evolution of hydrogen sulfide has nearly ceased,

the temperature of the reaction mixture may be of the reaction. The mixture is then filtered to remove the catalyst.

The surface active silica-containing solid cata- I lystsmay comprise activated clays, silicaalumi-. na cracking catalysts and the like. Thus, activated clays,'that is, natural clays such as bentonite, smectite, floridin, fullers earth and the like which have been treated with acid, such as are described in U. S. Patent No. 1,898,165, for example, may be advantageously employed. Synthetic silica-alumina catalysts of the type used for the cracking of hydrocarbon oils, examples ofwhich are described in U. S. Patent N0. 2,078,945 and U. S. Patent No. 2,283,173, may also be employed; Activated silica gel is also suitable. As my be seen, the term surface active-silicacontaining solid catalyst comprises a widevariety of materials, the predominant characteristic of which is the presence of silica in a surface active, that is, activated form.

In accordance with the present invention, an

alkylated phenyl phosphite is admixed with'the essentially parafiinic base lubricating oil and the mixture reacted with phosphorus pentasulfide as disclosed hereinabove; or the alkylated phenyl phosphite maybe added to the mixture of the phosphorus pentasulfide and the essentially paraifinic base lubricating oil during the reaction after the evolution of hydrogen sulfide has substantially ceased, but prior to completion of the reaction. The alkylated phenyl phosphite is ordinarily added in proportions ranging from to 75 per cent by Weight of its mixture with the paraifinic base lubricating oil, sufiicient to remove freeor corrosive sulfur in the phosphorus pentasulfide reaction product. Ordinarily not more than 50 per cent of the alkylated phenyl phosphite is sufficient for most purposes.

The alkylated phenyl phosphite used in our invention is prepared in accordance with U. S. Patent 2,253,227 from phosphorus trichloride and an alkylated phenol. As disclosed in said patent the alkylated phenols from which the alkylated phenyl phosphites are prepared are water-insoluble branched chain alkyl phenols having from 4 to 8 carbon atoms in an alkyl group. These alkylated phenols, in turn, are conveniently prepared by alkylating a simple phenol, such as phenol itself, the cresols or xylenols, with a suitable olefin in the presence of concentrated sulfuric acid as a catalyst in accordance with U. S. Patent 2,149,759 to Cantrell. Olefins such as butene-l, isobutylene, the amylenes (or mixtures of the preceding in refinery gas) and diisobutylene may be employed to produce the alkylated phenol. It is preferred to employ diisobutylene for the alkylation of the phenol since the resulting octyl (diisobutyl) phenol is primarily para-(alpha, alpha, gamma, gamma) tetramethylbutyl phenol. The phenols may be employed either singly or as a mixture.

Representative alkyl phenols which may be em-' ployed to prepare the alkylated phenyl phosphite used in accordance with our invention include:

6 2-tertiary-butyl-4,6-dimethyl phenol 2-tertiary-amyl-4,6-dimethy1 phenol 2,4,6-tri-tertiary-amyl phenol 2-tertiary-butyl-4,6-di-tertiary-amy1 phenol diisobutyl phenol The alkylated phenols are reacted with such an amount of phosphorus trichloride, in accordance with U. S. Patent 2,253,227, that the resulting alkylated phenyl phosphite contains from 1 to 5 per cent by weight of combined phosphorus; i. e., when working with an alkylated phenol having from 4 to 8 carbon atoms in a branched chain alkyl group, the .amount of phosphorus trichloride ranges from 5 to 30 per cent of the alkylated phenol. Such phosphites may therefore be defined as alkylated phenyl phosphites having from 4 to 8 carbon atoms in a branched chain'alkyl group and containing from 1 to 5 per cent by weight of combined phosphorus.

The following examples illustrate the preparation of our new improvement agents.

Example I Into a reaction vessel, there were placed 50 partsby weight of an essentially parafiinic base lubricating oil, which had been treated with aluminum chloride in accordance with our copending application Serial No. 718,902, and 50 parts by weight of an octyl (paratetramethylbutyl) phenyl phosphite. Then 12.5 parts by weight of phosphorus pentasulfide were added thereto. The mixture was agitated and heated to 490 F. in the course of one hour. After about 2 hours at this temperature, the evolution of hydrogen sulfide had substantially subsided. The temperature of the reaction mass was then raised to 520 F., and the mass agitated at this temperature for about 6 hours. The mixture was then cooled. The product had the following properties:

Gravity, API 8.4 Sulfur, per. cent. 4.6 Phosphorus, per cent 4.8 Neutralization No. 10-l2 Example II held at this temperature for 2 hours, and then the temperature was raised to 520 F. and held there for 6 hours. The product was then cooled and had the following properties:

Gravity, API 15 Viscosity, SUV 210 F. 133.3 Color, NPA 2.5 Phosphorus, per cent 3.28 Sulfur, per cent 3.0

Neutralization No. 11.4

Example III An additive was prepared in accordance with the procedure of Example I by reacting 37.5 parts by weight of an aluminum chloride treated essentially paraifinic base lubricating oil and 50 parts by weight of an octyl phenyl phosphite with 12.5 parts by weight of phosphorus pentasulfide.

The additive 1 thus". prepared hadflthe' following properties:

Neutralizationlio.

V I E im le' 'An additive was prepared in accordance with the procedure of Example I byreacting 81 parts by weight of an aluminum chloride treated es sentiall-y para-iiinic base lubricating oil and parts by weightofa'n octyl phenyl phosphite with S-parts by" 'veieh-t' of iphospliforus pentasulfide. The additiye thus; prepared had the following I ham er! I I An additive wasprepard in accordance with the procedureoffE'xampl'e I by reacting 68.4parts by weight of an aluminum. chloride treated es- 8" Phosphorus; per cent 3.9 Neutralization No. 6.0

Example VII 7 An' additive was prepared in accordance with the procedure of Example I by reacting 37.5 parts by weight of an aluminum chloride treated parafiinic base lubricating oil, 50 parts by weight of an octyl phenyl phosphite and 12.5 arts by weight of phosphorus pentasulfide, in the presence of 10% activated clay. The additive thus prepared had the. following properties:

Gravity, API 9.4 Viscosity, SUV 210 F 421 Color, NPA 1.0 Sulfur, per cent 3.7 Phosphorus, per cent 4.0 Neutralization No. 37.0

The reaction products obtained in accordance With the preceding examples are excellent improveinent agents for mineral oil lubricant compositions. They are light colored and readily soluble in all types of mineral oils, that is paraffinic, naphthenic or mixed base mineral oils and, as a matter of fact, can be blended with mineral oils in proportions as high as 50 per cent by Weight or higher. This excellent solubility of our'new improvement agents enables the preparation of concentrated solutions, which may "52o wi imm as? i fi p i i then be diluted down to the proportion desired i b Qctyl pheny 1p osp 1 e in the final mineral oil lubricant composition. WWW Wm ph r s peptasulfide' As stated our new improvement agents confer Th f d iw t followlrtg propel-mes excellent antioxidant and I corrosion-inhibiting G t -+V properties on the mineral lubricating oils with VI EO W,: 4 105-3 which they are incorporated, and are charac- Color', N-PA: terized by a high degree'of potency at high tem- 7 311-1111;, per cent r 5 peratures. For these purposes, our new improve- Phosphorus, per cent ment agents are generally added to mineral oils Neutralization N0. 1 in minor amounts, say frontal; to 20 per cent by Example VI Wei h; of llninegaloil, sufiicient to confer im- Into a reaction essel Wereplaced 50 parts y move an 3 and orslpmmp'lbltl-ng 1 V v V p b propert1es on the mineral lubricating oils with sulvent refined b n which they are incorporated Lubricatin ils V eating-oilwhich had not-beentreated with alumicohtainihg; our p-f vm a o num chloride and 50 pa-rtsby weight of an octyl cessfuny pass se Copper Strip Test g 8 Sue: mar t g b trli sh l t T The following examples illustrate the use of P b h l a parts our new improvement agents to obtain improved y-"we Phosphorus palm-Sulfide were added mineral oillubricant compositions and the mixture was heated and agitated atiOO I 7 H The mixture was held at this temperature for Example VIII 2 hours and thenthe' temperature'was raised An improved motor oflwas f i 1 ,r prepared by blendto 2 and h there fur r The mg 1 per" cent by weight of the additive of Ext r was theneooled. The pro u t hadt arnple II with 99"per cent by weightof a solvent lowingpropertiesz p Q 1 refined 'paraffinic motor oil: (5. A. E. 30). A Gravity, API n.. 7.9 5 comparison 'ofthe properties of" the improved Sulfur, per cent I I Ii a'IIlI' and" the basedubricant follows:

. ttbaialt 1 332??? e t 1API i V vi ifiiiy; SUV: 100F 2 13; 2 W. .N. Viscosity Index; 104. 102 Flash-QC: F l 455 470 8 si 'eae' -J0 61- H Oxgigtion 51d Bear g com passes f g V .Me'thod 257, Gulf: I 7 A Duration of Test: Hrs 4g 48 Oil Bath Temperature: F 347 347 Quantity of 011: cc 300- 300 Air Bate: cc/hr 2,000 2'000 v Beams P ice-Ac. CuJ b .od-A ouL Wt. Change: Grams.-. -o.2o40 o.315o Y +0.-0021- +0.0s23 .M H V xvtbghgicgee: Per Cent I. -j0; 'l.42 +;0.0l* '+O.3l chevr blet 36 aa's nagsmareee p ted Wed l Designation L-4: 3 a

'Engine Condition Rating .75 94 Bearing Loss: MgJWhole Bearing. "5411i; 54

Erample IX the improved motor lubricant and the base lubriingl per cent bywweight of the additive of Example III with 99 per cent by weight of an S. A. E. motor oil. A comparison of the properties of the improved lubricant andthe base lubricant Unimproved Improved Lubricant Lubricant Gravity: API 28.1 28.3 Viscosity, SUV: 100F 549 558 Viscosity Index 104 102 455 460 4. 25 4. 5 passes pagses 0 Oxidation and Be 111g Corrosion Test' Method 257, Gulf:

Duration of Test: hr 48 48 011 Bath Temperature: F 347 347 Quantity of Oil: cc 300 300 Air Bate: cc./hr 2, 000 V v r 2, 000 Bearing Type Cd-Ag Cu-Pb Cd-Ag Cu-Pb Wt. Change: Grams 0. 2040 0;3150 +0. 0023 +0. 0614 Wt. Change: Per Cent 0. 93 1.42 +0.01. +0.032 Appearance r. pitted pitted bright coated Chevrolet 36 HI. Engine Test, CRC Desrgnation L-4:

Engine Condition Rating ,95 Bearing Loss: MgJWhole Bearing 541 26 Example-XI An improved motor oil was prepared .bylblending 1 per cent by weight of the additive or ample V with 99 per cent by weight of ans. A,

30 motor oil. A comparison of the properties follows:

Unimproved Improved Lubricant Lubricant Gravity API 28 1 28.3 Viscosity, SUV: 100F. 549 I 558 Viscosity Index 104 102 Flash, 00: F.. 455 460 Color, NPA 4. 25 4. 5 Copper Strip Test passes passes Neutralization N 0. Oxidation and Bearing Corrosion Test Method 257, Gulf:

Duration of Test: hr 48 48 Oil Beth Temperature: F 347 347 Quantity 01011: cc 300 300 Air Rate: cc./hr 2,000 2,000 Bearing Type Cd-Ag C11Pb Cd-Ag Cu-Pb Wt Change Grams -0. 3150 +0 0019 +0 0599 Wt Change Per Ce -0.93 '1.42 0.01 0.31 Ap e ranc pitted pitted bright coated Chevrolet 36 Hr Engine T nation L-4: I

Engine Condition Rating 75 92 Bearing Loss: MgJWhole Bearing.-." 541 74 Ezpcmple X Animproved motor oil was prepared. by blendof the improved motor lubricant lubricant follows P and the base -Unirnproved Improved Lubricant Lubricant Gravity: API 28.1 28.3 Viscosity, SUV: 100 F 549 558 Viscosity Index 104 102 Flash, 00: F 455 465 Color, NPA 4.25 4. 5 Copper Str1 p Test passes passes Neutralization No 0. 0

Oxidation andBearing Corros on Test '7 I Method 257, Gulf.

Duration'oi Test: Hr Oil Bath Temperature: F.. Quantity of 011: cc.

Appearance Chevrolet 36 Hr. Engine Test, nation L-4:

Engine Condition Rating Bearing Loss: Mg./Whole Bearing r 11 according to Example VI with :99 per cent by weight of a solvent refined parafiinic mptor oil S. A. E. 30. The properties of the improved and unimproved motor oils were as follows:

Unimproved Motor Oil Improved Motor Oil Gravity:

Viscosity, SUV: 100 Viscosity Index 104 Flash, F. 455 Color, NPA 4. 25 Copper Strip Test, 212F., 3 Hr passes Oxidation and Bearing Corrosion Test Method 257, Gulf:

Duration 01 Test: Hr

Oil Bath Temperature: F-

Quantity of Oil: co,

ear ng Type ediA -Wt. Chan e: Gram ,0.o42

Wt. Changes: Per .0 -i ),02 b s i Appearance +0. 752 +0. 33 coated 7 Example XIII Anim'proved motor oil was prepared by blending 1 per cent by weight of the additive, prepared according to Example VII, with 99 per cent by ing the effectiveness of various improvement agents, the usual procedure is to run a blank test simultaneously with the oil composition being tested, employing forthat purpose a sample of o1vent parafinic motor A. 30., 'ompar-ison of the improved and 1 improvedmotor oils are as follows:

to employ commercial bearing shells. These shells comprise a suitable metal backing faced Unimproved Motor Improved Motor Oil 011 Gravity: API 28.1 28.3 Viscosity, SUV: 100" F 549 560 Viscosity Index 104 m4 Flash, 00: "F

455 115 Color, NPA 1. 4. 25 Copper Strip Test, 212 F., 3 Hr passes passes Oxidation and Bearing Corrosion Test Method 257, Gulf: 7

Duration of Test: hr 48 55 Oil Beth Temperature:F 347 347 Quantity of 011: cc. 300 300 Air Rate: cc./Hr. '2, 000 2, 000

Bearing Type. Cd-Ag Cu-Pb Cd-Ag C r-Pb h Wt. Change: Gra 0.2040 0. 3150 +0. 004 +0. 0523 Wt. Change: Per Cent.. -0.93 .-1.44 +0.03 +0.15

Appearance pitted pitted bright coated Example XIV with the alloy bearing metal. his way the In order to determine the comparative improvement in properties obtained by using the additive of the present invention, additives prepared in accordance with the disclosures of Serial No. 718,902, Serial No. 736,618, now U. S. Patent No. 2,456,336, and the present invention were subjected to the well known Copper Strip Test. In each instance 1 part'by weight of the additive was compounded with 99 parts by weight of a highly refined motor oil. The uncompounded oil is included for purposes of compa son.

:- a case lubricant is evaluated with respect to. its

actual bearing face is subjected to severe deterioration conditions. By comparison of the results of such tests with actual service tests, we have found them to be in substantial agreement as to suitability or particular lubricants.

The Chevrolet 36 Hour Engine Test referred to above is an accepted standard test designed to determine the oxidation, bearing corrosion.

and detergency characteristics of engine crank case oils designed for use under heavy duty service conditions. In this procedure, the crank Uncorn- Lubricant Lubricant Lubricant pounded of S. N. of 8. N. oi Present Lubricant 718,902 736,618 Invention Gravity: API 28.1 27.8 28.2 28.3 549 544 551; 554

passes tarnished tarnished passes The Oxidation and, Bearing Corrosion Test, Method 257 Gulf referred to in the foregoing examples is conducted as follows;

mensions is surmerged in 300 cc. of the oil or oil composition to be tested in a 400 cc. Pyrex beaker and heated in a thermostatic oil bath to 347 F. Air is then bubbled through the oil in contact 1 stability or resistance to oxidation, bearing cor- 1rps1on and the deposition of contaminants re- An alloy bear;-- ing shell of certain commonly used standard diwith the bearing shell at a rate of 200.0 cc. per 75 sulting from decomposition and oxidation or other changes that occur in the lubricant in I 13 g each test a complete set of new piston rings is installed and two new weighed copper-lead test bearings are installed in symmetrical location. Performance of the test oil is judged by examination of thepower section of the engine for deposits and by ascertaining the weight loss ofthe test bearings. The detergency characteristics are expressed as Engine Condition Rating and indicate the freedom from engine deposits expressed in per cent, the larger the per cent (approaching 100 as a limit) the cleaner the engine. The amount of bearing corrosion is indicated as Bearing Loss and is expressed in milligrams loss in weight of the standard bearing.

As shown in the above examples, the addition of our new improvement agents to mineral oil lubricant compositionsconfers excellent detergency, antioxidant and corrosion-inhibitingprop erties. At the same time the compositions so obtained are stable in storage and use and have a color which is substantially unaffected by the addition of the improvement agent. The lubricants obtained pass the Copper Strip Test.

While we have shown in the examples the preparation of compounded lubricating oils, our

invention is not limitedthereto but comprises all mineral oil lubricant'compositions containing our new improvement agents, such as greases and the like. Furthermore, conventional addition agents such as viscosity index improvers, pour point depressants, anti-foam agents and the like may be added without departing from the spirit of the invention. What we claim is: 1. The process of preparing an improvement agent for mineral oil lubricants which comprises heating an essentially parafiinic base lubricating oil with anhydrous aluminum chloride at a tem-' perature of from 150 to 300 F., removing aluminum chloride from the reaction product, and reacting said product and from 10 to 75 per cent by weight of its mixture with said product of an alkylated phenyl phosphite with phosphorus pentasulfide at an elevated temperature not .below 300 F. and not in excess of the minimum cracking temperature of said product to incorporate phosphorus and sulfur therein.

2. The process of preparing an improvement agent for mineral oil lubricants which comprises heating an essentially paraffinic base lubricating oil with anhydrous aluminum chloride at a temperature of from 150 to 300 F., removing aluminum chloride from the reaction product, and reacting said product and from 10 to 75 per cent by weight of its mixture with said product of an alkylated phenyl phosphite with phosphorus pentasulfide at a'temperature of from 450 F. to

a maximum temperature below the minimum cracking temperature of said product to incorporate phosphorus and sulfur therein.

3. The process of preparing an improvement agent for mineral oil lubricants which comprises heating an essentially paraffinio base lubricating oil with from 1 to 20 per cent by weight on said oil of anhydrous aluminum chloride at a temperature of from 150 to 300 F., removing aluminum chloride from the reaction product,

and reacting said product and an alkylated phenyl phosphite in an amount of from 10 to 75 per cent by weight of its mixture with said product with from 2 to 20 per cent by weight of said mixture or phosphorus pentasulfide at a temperature of from 450 F. to a maximum temperature below the minimum cracking of said 14 product to incorporate phosphorus and sulfur therein. I

4. The process of claim 3, wherein the product is dissolvedin a mineral lubricating oil.

5. The process of claimB, whereinthe alkylated phenyl phosphite contains from 4 to '8 carbon atoms in a branched chain alkyl group, and contains from 1 to 5 per cent byweight ofcombined phosphorus. o

6. The process of claim 5, wherein the alkylated phenyl phosphite is para-tetramethylbutyl phenyl phosphite. I I

7. The process of preparing an improvement agent for mineral oil lubricants which comprises heating an essentially paraifinic base lubricating oil with phosphorus pentasulfide in the presence of a surface active silica-containing solid catalyst and an alkylated phenyl phosphite having from 4 to 8. carbon atoms in a branched chain alkyl group in an amount of from 10 to '75 per cent by weight of its mixture with said oil at a temperature of from 300 F. to a maximum temperature below the minimum cracking temperature of said lubricatingoil to incorporate phosphorus and sulfur therein.

8. The process of preparing an improvement agent for mineral oil lubricants which comprises heating an essentially paraffinic base lubricating oil and an alkylated phenyl phosphite in an amount of from 10 to Super cent by weight of its mixture with said oil with from 2 to 20 per cent by weight of said mixture of phosphorus pentasulfide in the presence of from 2 to 25 per cent by weight of the reaction mixture of a surface active silica-containing solid catalyst at a temperature of from 300 F. to a maximum temperature below the minimum cracking temperature of said lubricating oil to incorporatephosphorus and sulfur therein.

9. The process of claim 8, wherein the alkylated phenyl phosphite contains from 4 to 8 carbon atoms in a branched chain alkyl group and contains from 1 to 5 per cent of combined phosing oil with from 1 to 20 per cent by weightof said oil of'anhydrous aluminum chloride at a temperature of from 150 to 300 F., removing aluminum chloride from the reaction product.

heating said product with from 2 to 20 per cent by weight on the mixture of said product and the alkylated phenyl phosphite hereinafter described of phosphorus pentasulfide in the presence of a surface active silica-containing solid catalyst and an alkylated phenyl phosphite having from 4 to 8 carbon atoms in a branched chain alkyl group in an amount of from 10 to percent by weight of its mixture with said product at a temperature of from 300 F. to a maximum temperature below the minimum cracking temperature of the aluminum chloride treated oil to incorporate phosphorus and sulfur therein.

12. The product obtained by the process of claim 1.

l 13. The product obtained by the process of I 1-5 r 15. The product obtained by the process of claim 7.

1,6. The

vproduct obtained by the process of claim '11.

' V v 17. Ar'lubricant composition comprising a major amount of a mineral lubricating oil and a minor amount, sufficient to confer improved antioxidant and corrosion inhibiting properties on the composition, of the product obtained by the process of claim 1.

' 13. 3 lubricant composition; comprising a major amount of a mineral lubricating oil and a minor amount, sufiicient to confer improved antioxidant and corrosion inhibiting properties onpthe composition, of the product obtained by the process of claim 3. r r 7 "I19; A lubricant composition comprising a major amount of a mineral lubricating oil and a minor amount sufficient to confer improved antioxidant and corrosion "inhibiting properties of the product obtained .16 on the composition, of the product obtained by the process of claim '7. I r 20. A lubricant composition comprising a major amount of a mineral lubricating oil and a minor amount, sufficient to confer improved antioxidant'and corrosion inhibiting properties, by the process of claim 11. HERSCHEL G. SMITH. TROY L. C'ANTRELL'.

REFERENCES CITED UNITED STATES PATENTS Number Name Date 2,253,227 Cantrell et a1 Aug.'19, 1941 2,449,934 Giammaria V Sept. 21, 1948 Smith et a1. Dec. 14, 1948 

1. THE PROCESS OF PREPARING AN IMPROVEMENT AGENT FOR MINERAL OIL LUBRICANTS WHICH COMPRISES HEATING AN ESSENTIALLY PARAFFINIC BASE LUBRICATING OIL WITH ANHYDROUS ALUMINUM CHLORIDE AT A TEMPERATURE OF FROM 150* TO 300* F., REMOVING ALUMINUM CHLORIDE FROM THE REACTION PRODUCT, AND REACTING SAID PRODUCT AND FROM 10 TO 75 PER CENT BY WEIGHT OF ITS MIXTURE WITH SAID PRODUCT OF AN ALKYLATED PHENYL PHOSPHITE WITH PHOSPHORUS PENTASULFIIDE AT AN ELEVATED TEMPERATURE NOT BELOW 300* F. AND NOT IN EXCESS OF THE MINIMUM CRACKING TEMPERATURE OF SAID PRODUCT TO INCORPORATE PHOSPHORUS AND SULFUR THEREIN. 